Is that really the case?
I view reasonable and fully disclosed self-promotion as qualitatively different than spam and something that should be treated differently. Even HN makes this distinction by having a show section where self-promotion is allowed, but still blocking random spam.
Here's an example of self-promotion: "Hi, I'm Joe, the founder of Flextape. Watch me saw this oil tanker in half. Environmental disaster? No, we have flextape. Bam, good as new! Ask me anything."
Here's an example of spam: "These viagra pills are the best. Cheapest price! Send $69 they send you big box today!"
Now, I can understand that some communities don't want to allow self-promotion and might block self-promotional posts. But I'm not sure that treating an honest entrepreneur the same as a viagra spammer with a site-wide ban is the right approach for Reddit.
So you are correct - Show HNs are content for which HN has an appetite. OPs content might be received just fine as a 'Show HN'. But on reddit, with the way they approached it, it is spam.
Is one self-promotional post on Reddit ok by your standards?
If one is ok, is 2 ok? How about 3? Where should we draw the line? Is it ok to make 1 self-promotional post every year? Every 6 months? Every month? Every week?
What if subreddit rules allow self-promotional content? Would posting there be ok?
> when it adds no value to the audience.
If only Reddit had a system for rating content.....(see the following)
> The post got a lot of traction with 200k views and 1.5k upvotes within 8 hours and lots of comments asking questions about it and some saying how helpful this could be.
This is not "Reddit doesn't allow startups." -- This is "Reddit doesn't allow spam."
If you want to advertise to a community, first you need to actually participate in that community. If it makes you feel any better about it, you probably aren't missing out on much. My experience is that reddit gives you traffic, but not customers.